Software engineering is defined as a process of analyzing user requirements and then designing, building, and testing software application which will satisfy those requirements. ... It helps you to obtain, economically, software which is reliable and works efficiently on the real machines

1. A Fundamental Approach to
Software Engineering
By
Dr. Bechoo Lal
Western College, University of Mumbai
Scientific Engineering and Computing Research by Dr. Bechoo Lal

2. Contents
 Introduction
 Software Paradigm
 Software Engineering Concepts/ Process
 Software Development Life Cycle
 Software Process Model
 Need of Software Project Management
 Design Methodology/ Concepts
 Coding
 Testing
 Summary
Scientific Engineering and Computing Research by Dr. Bechoo Lal

3. Introduction
 Software is more than just a program code. A program
is an executable code, which serves some computational
purpose.
 Engineering on the other hand, is all about developing
products, using well-defined, scientific principles and
methods.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

4. Definition
IEEE defines software engineering as:
The application of a
 Systematic,
 Disciplined,
 Quantifiable approach to the development,
 Operation and maintenance of software; this is the application of
engineering to software.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

5. Software Paradigms
Software paradigms refer to the methods
and steps, which are taken while designing
the software.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

6. Software Engineering Concepts
Scientific Engineering and Computing Research by Dr. Bechoo Lal

7. Need of Software Engineering
Large Software
Scalability
Cost
Dynamic Nature
Quality management
Scientific Engineering and Computing Research by Dr. Bechoo Lal

8. Software Development Process
Scientific Engineering and Computing Research by Dr. Bechoo Lal
“A Process is a sequence of steps executed to
achieve a goal”

9. Software Development Life Cycle(SDLC)
Scientific Engineering and Computing Research by Dr. Bechoo Lal

10. Software Process Models
Waterfall Model
Prototype Model
Iterative Development Model
Spiral Model
Rapid Application Development
Time boxing Model
Extreme Programming/ Agile Model
Scientific Engineering and Computing Research by Dr. Bechoo Lal

11. Software Development Paradigm
 Waterfall Model: This model is the simplest model of software development
paradigm.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

12. Advantages of Waterfall Model
Simple and easy to understand and
use
Easy to manage
Clearly defined stages
Easy to arrange task
Process and result are well
documented
Scientific Engineering and Computing Research by Dr. Bechoo Lal

13. Disadvantages of Waterfall Model
High amount of risk and uncertainty
Not a good model for complex and object
oriented projects
Cannot accommodate changing requirement
Poor model for long and outgoing projects
Scientific Engineering and Computing Research by Dr. Bechoo Lal

14. Iterative Process Model
The iterative model is a particular
implementation of a software
development life cycle (SDLC) that
focuses on an initial, simplified
implementation, which then progressively
gains more complexity and a broader
feature set until the final system is
complete
Scientific Engineering and Computing Research by Dr. Bechoo Lal

15. Spiral model of the software process
Scientific Engineering and Computing Research by Dr. Bechoo Lal
Risk
analysis
Risk
analysis
Risk
analysis
Risk
analysis Proto-
type 1
Prototype 2
Prototype 3
Opera-
tional
protoype
Concept of
Operation
Simulations, models, benchmarks
S/W
requirements
Requirement
validation
Design
V&V
Product
design Detailed
design
Code
Unit test
Integration
testAcceptance
testService Develop, verify
next-level product
Evaluate alternatives
identify, resolve risks
Determine objectives
alternatives and
constraints
Plan next phase
Integration
and test plan
Development
plan
Requirements plan
Life-cycle plan
REVIEW

16. Spiral Model
 Objective setting
 Specific objectives for the phase are identified
 Risk assessment and reduction
 Risks are assessed and activities put in place to reduce the key
risks
 Development and validation
 A development model for the system is chosen which can be
any of the generic models
 Planning
 The project is reviewed and the next phase of the spiral is
planned
Scientific Engineering and Computing Research by Dr. Bechoo Lal

17. The Prototyping Process
Scientific Engineering and Computing Research by Dr. Bechoo Lal
Identify
Initial
Requirements
Develop
System
Use and
Evaluate
Document and Install
Iterate

18. Prototyping Life Cycle
 Determine suitability for prototyping
 Identify basic needs
 Develop working model
 Demonstrate and solicit refinements
 Revise and re-demonstrate
 Clean up and document
Scientific Engineering and Computing Research by Dr. Bechoo Lal

19. RAD: Team Based Software
Development
Scientific Engineering and Computing Research by Dr. Bechoo Lal

20. Agile Model
Scientific Engineering and Computing Research by Dr. Bechoo Lal

21. Agile Process Model…
The Agile model adopts Iterative
development. Each incremental part is
developed over an iteration.
Each iteration is intended to be small and
easily manageable and that can be completed
within a couple of weeks only.
At a time one iteration is planned, developed
and deployed to the customers
Scientific Engineering and Computing Research by Dr. Bechoo Lal

22. Agile Model…
Scientific Engineering and Computing Research by Dr. Bechoo Lal

23. Agile Model…
Scientific Engineering and Computing Research by Dr. Bechoo Lal

24. Design Methodology and Concept
 Modular Decomposition
 Coupling- Interconnection between modules
 Cohesion- Tightly bound the internal elements of module.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

25. Design Methodology
Restate the problem as data flow diagram
Identify the input and output data elements
First level factoring
Factoring for input / output and transform
branches
Scientific Engineering and Computing Research by Dr. Bechoo Lal

26. Coding/ Programming
Structured Programming
Information Hiding/ Security
Pair Programming
Refactoring- Making changes to
some existing code.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

27. Testing
Unit Testing- Code based
Integration Testing- Design specification
System Testing- Requirements Specification
Acceptance Testing- Client Needs
Scientific Engineering and Computing Research by Dr. Bechoo Lal

28. Summary
Software engineering playing a
significant role in every aspect of
software development and control
the development processes within
time , resources, budget
constraints and provides a quality
oriented software.
Scientific Engineering and Computing Research by Dr. Bechoo Lal

29. Thanks !!!
Questions and Answers
BLAL2k7@gmail.com
Scientific Engineering and Computing Research by Dr. Bechoo Lal